Johnathan Horton Jr. — initially believed to be 2 years old by police — was unresponsive when police officers and firefighters arrived at the home near North Seventh Avenue and Union Hills Drive, according to Sgt. Vince Lewis, a Phoenix police spokesman.

The boy was taken to a hospital and pronounced dead, police said.

Though police don't suspect foul play, Lewis said, the Maricopa County Medical Examiner will investigate how the boy died.

"A death of a child as small as this one is to be investigated, regardless," Lewis told The Republic.